Control method of cooling fan, and information processing device

ABSTRACT

A voltage supplied to a cooling fan  305  is adjusted in accordance with a temperature measured near a central processing unit  401.  At this time, different tables of temperatures and supplied voltages are referred to depending upon whether or not an external memory device is mounted, whereby suitable control of the cooling fan  305  is performed in accordance with an attaching-detaching state of the external memory device in an information processing device that permits internal mounting of the external memory device.

TECHNICAL FIELD

[0001] The present invention relates to the cooling of an informationprocessing device, and particularly, relates to the control of a coolingfan in the information processing device to which an external memorydevice, etc. can be detachably attached.

BACKGROUND OF THE INVENTION

[0002] A microprocessor such as a central processing unit, etc.,arranged in an information processing device generates heat during itsoperation. A cooling fan is arranged in the information processingdevice to prevent an operation error due to this heat, an influence ofthis heat on lifetime, etc.

[0003] Since, however, the cooling fan generates noises depending upon arotation speed, it is desirable to set the rotation speed of the coolingfan to a necessary minimum limit. There is therefore known a techniquefor arranging a temperature sensor near the central processing unit, andadjusting the rotation speed of the cooling fan on the basis of atemperature near the central processing unit.

[0004] In recent years, compactness of the information processing deviceis advanced, and an external memory device, a memory medium reader,etc., which are conventionally often designed as a built-in fixing type,are designed as an attaching-detaching type for further improvingportability, etc. or coping with the diversity of a use mode of a user,etc. In this case, it is considered desirable to permit internalmounting of the “external” memory device, memory medium reader, etc.,instead of their external mounting in view of usability at a mountingtime, outer appearance, etc.

DISCLOSURE OF THE INVENTION

[0005] However, when the “external” memory device of theattaching-detaching type, etc. are internally mountable, the externalmemory device, etc. themselves constitute new heat sources within theinformation processing device during the mounting, and are objects to becooled. Further, it is considered that the paths of cooling air currentsare changed depending upon whether they are mounted or not mounted.Therefore, no sufficient cooling effects may possibly be obtained in thecooling fan control similar to that during non-mounting time.

[0006] An object of the present invention is to provide an informationprocessing device that permits internal mounting of an “external” memorydevice, etc., in which suitable control of the cooling fan is performeddepending upon an attaching-detaching state of the external memorydevice, etc.

[0007] For overcoming the above problems, the present invention providesa method of controlling a cooling fan in an information processingdevice that permits internal mounting of a relevant device, comprisingthe stages of:

[0008] obtaining an internal temperature of the information processingdevice;

[0009] obtaining an attaching-detaching state of the relevant device;

[0010] obtaining a value relative to a rotation speed of the cooling fanwhich rotation speed corresponds to the obtained temperature, byreferring to data which shows the relationship between the valuerelative to the rotation speed of the cooling fan and the temperature,and is determined depending upon the attaching-detaching state of therelevant device; and

[0011] controlling the rotation speed of the cooling fan on the basis ofthe value relative to the rotation speed of the cooling fan.

[0012] The above relevant device refers to an external memory device, amemory medium reader, etc.

[0013] The present invention also provides an information processingdevice that permits internal mounting of a relevant device, comprising;

[0014] a cooling fan having variable rotation speeds, temperatureobtaining means for obtaining a temperature within the informationprocessing device, attaching-detaching state obtaining means forobtaining an attaching-detaching state of the relevant device, controlmeans for controlling the rotation speed of the cooling fan, andreference data that shows the relationship between a value relative tothe rotation speed of the cooling fan and the temperature and isdetermined depending upon attaching-detaching state of the relevantdevice,

[0015] wherein said control means determines the reference data to bereferred to, on the basis of the attaching-detaching state of therelevant device obtained by the attaching-detaching state obtainingmeans, calculates the value relative to the rotation speed of thecooling fan from the temperature obtained by the temperature obtainingmeans and said reference data, and controls the rotation speed of thecooling fan on the basis of the obtained value.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is an explanatory view showing the shapes of threeconstructional members of a box body 100 of an entertainment apparatusin one embodiment of the present invention.

[0017]FIG. 2 is a perspective view showing a state in which an upper boxbody is removed from the box body 100 of the entertainment apparatus inone embodiment of the present invention.

[0018]FIG. 3 is a perspective view showing a rear face of the box body100 of the entertainment apparatus in one embodiment of the presentinvention.

[0019]FIG. 4 is a cross-sectional view showing the entire constructionof the entertainment apparatus in one embodiment of the presentinvention.

[0020]FIG. 5 is a perspective view showing a state in which anintermediate plate is removed from the box body 100 of the entertainmentapparatus in one embodiment of the present invention.

[0021]FIG. 6 is a side view of a main board 381.

[0022]FIG. 7 is a schematic view of layout of main parts of a mainsubstrate 381 a.

[0023]FIG. 8 is a schematic view of layout of main parts of a powersubstrate 381 b.

[0024]FIG. 9 is a schematic view of a correspondence table for fancontrol as one example of data for use in the control of a cooling fan.

[0025]FIG. 10 is a flow chart for explaining a processing flow of amicrocontroller 411.

BEST MODE FOR CARRYING OUT THE INVENTION

[0026] An embodiment of the present invention will be explained withregard to a case of application of the present invention to anentertainment apparatus as an information processing device withreference to the drawings. While the present invention is not limited tothe entertainment apparatus, the present invention is more effectivewhen applied to a device that is limited in appearance, size, parts tobe used, etc. to a certain extent as in the entertainment apparatus forwide popularization thereof.

[0027] A box body 100 of the entertainment apparatus in this embodimentis constituted of three portions as shown in FIG. 1. Namely, the boxbody 100 is constituted of an upper box body 110, a central chassis 140and a lower box body 170. Each of the upper box body 110 and the lowerbox body 170 generally has a flat rectangular parallelepiped shape. Theupper box body 110, the central chassis 140 and the lower box body 170are fixed and integrated with bolts that are not shown.

[0028] The central chassis 140 has a rear face portion 141 and anintermediate plate 142. This intermediate plate 142 partitions a spacewithin the box body 100 into a storing space on the upper box body 110side and a storing space on the lower box body 170 side. Thisintermediate plate 142 has, mounted thereon, various kinds of devicesstored into the upper box body 110. Examples of the devices mounted onthe intermediate plate 142 include a disk unit 310, a slot unit 301, apower unit 302 and a switch-inlet unit 304 as shown in FIG. 2. A throughhole 142 b and a through hole 142 c are also made in the intermediateplate 142 (see FIG. 1). A hood 142 d is arranged in the intermediateplate 142 so as to cover the through hole 142 b. A radiation fin 306(see FIG. 2) arranged in the lower box body 170 extends through thethrough hole 142 b, and is stored into the hood 142 d. A notch portion142 a is formed in the intermediate plate 142 and a cooling fan 305 isarranged in the intermediate plate 142. The slot unit 301 is fastened toa projection arranged on an upper face of the intermediate plate 142with a screw so that the slot unit 301 is fixed to the intermediateplate 142.

[0029] The disk unit 310 is a recording medium drive unit forreproducing a disk type recording medium such as CD, DVD, etc., and hasa tray (not shown) capable of sliding in and out. The disk typerecording medium is to be mounted on the tray. A reproduction portionfor storing the tray to reproduce the disk such as CD, DVD, etc. mountedon the tray is built in the disk unit 310.

[0030] As shown in FIG. 3, a notch portion 143 a is formed in the rearface portion 141 of the central chassis 140. The switch-inlet unit 304is exposed from the notch portion 143 a to the exterior. An exhaust port143 b is formed in a position where the rear face portion 141 faces thecooling fan 305. In addition thereto, as shown in FIG. 3, various kindsof communication terminals 521, 522 are arranged in a lower rear facemember 144. An opening portion 523 as an insertion port of an externalmemory device of an attaching-detaching type is made in the rear faceportion 141. In a normal using state, the opening portion 523 is coveredwith a cover that is not shown.

[0031] As shown in FIG. 4, a main board 381 having a central processingunit 401 mounted thereon is arranged in the lower box body 170. Further,as shown in FIG. 5, a storing case 391 of the external memory device ofthe attaching-detaching type and a ventilation port 190 are arranged inthe lower box body 170 together with the main board 381.

[0032] As shown in FIG. 6, the main board 381 has a two-layeredstructure constituted of a main substrate 381 a and a substrate 381 bfor power. A heat sink 307 integrated with the radiation fin 306 and ashield 308 formed of a metallic plate are arranged between the twosubstrates. Required circuits can be efficiently stored in a limitedspace by forming the above two-layer structure in which the heat sinkand the shield are sandwiched between the substrates.

[0033] As shown in FIG. 7, the central processing unit 401, a mainmemory device 402 and a drawing processor 403 are arranged as main partsin the main substrate 381 a. A temperature sensor 404 is also arrangedin the vicinity of the central processing unit 401. Further, a connectorportion 405 to be used for electric connection with the power substrate381 b and a signal line cable 406 to work as a signal path of data whenthe external memory device is mounted are further arranged on the mainsubstrate 381 a.

[0034] Heat is generated by operation of the central processing unit401, etc. arranged on the main substrate 381 a. This heat is conductedto the heat sink 307 and is further conducted to the radiation fin 306.The air taken-in from the ventilation port 190 passes between respectivefins of the radiation fin 306 when the air flows toward the cooling fan305, whereby the air absorbs heat from the radiation fin 306. The air isexhausted from the cooling fan 305 to the exterior.

[0035] As shown in FIG. 8, the power substrate 381 b is provided with amicrocontroller 411 for controlling a voltage supplied to each devicewithin the entertainment apparatus, a connector portion 412 to be usedfor electric connection with the main substrate 381 a, an externalmemory device power line 413 for supplying the voltage when the externalmemory device is mounted, and a cooling fan power line 414 for supplyingthe voltage to the cooling fan 305. The microcontroller 411 candetermine whether or not the external memory device is mounted bymonitoring a state of the power line 413 of the external memory device.Further, the microcontroller 411 can obtain a temperature measured bythe temperature sensor 404 through the connector portion 405 of the mainsubstrate 381 a and the connector portion 412 of the power substrate 381b.

[0036] A general-purpose hard disk drive unit can be used as theexternal memory device to be mounted on this entertainment apparatus.The hard disk drive unit has a power connector portion and a data lineconnector portion. The external memory device power line 413 from theentertainment apparatus is connected to the power connector portion, andthe signal line cable 406 is connected to the data line connectorportion, so that the external memory device attains an operable state.The external memory device can then transmit and receive data inaccordance with commands from the entertainment apparatus.

[0037] At this time, the external memory device can be stored to astoring case 391, and attains a fixing state by closing a cover, so thatthe external memory device is stored in the entertainment apparatus.

[0038] Control of the cooling fan in the entertainment apparatus of theabove construction will be explained below.

[0039] In this embodiment, the microcontroller 411 has a correspondencetable for the fan control as data to be used for the control of thecooling fan, for example, as schematically shown in FIG. 9. There may beemployed a constitution in which the data to be used for the fan controlis stored in the exterior of the microcontroller 411 and is referred toby the microcontroller 411. A format and values of the data to be usedfor the fan control are not limited to the example of this Figure. Forexample, a table format, a program format, etc., may be employed.

[0040] In the correspondence table for the fan control in this Figure,the axis of ordinate shows the value of a voltage supplied to thecooling fan 305, and the axis of abscissa shows the temperature measuredby the temperature sensor 404 arranged in the vicinity of the centralprocessing unit 401. This table shows the relationship between atemperature range and the supplied voltage when the external memorydevice is mounted (a graph shown by a broken line) or not mounted (agraph shown by a solid line). The above temperature range applied withrespect to a certain supplied voltage is called a temperature zone. Aplurality of temperature zones are set for each of the time periods whenthe external memory device is mounted and not mounted.

[0041] Namely, when a certain temperature zone corresponding to themeasured temperature is applied, and when the temperature rises andexceeds an upper limit of the present temperature zone, the presenttemperature zone is changed to a temperature zone for increasing thesupplied voltage to the cooling fan 305, to increase the rotation numberof the cooling fan 305. Conversely, when the temperature decreases to belower than a lower limit of the present temperature zone, the presenttemperature zone is changed to a temperature zone for decreasing thesupplied voltage to the cooling fan 305, to decrease the rotation numberof the cooling fan 305. The voltage corresponding to the measuredtemperature can be accordingly supplied to the cooling fan 305.

[0042] As can be seen from this Figure, when the temperatures are at thesame level, the microcontroller 411 supplies a higher voltage to thecooling fan 305 when the external memory device is mounted than when theexternal memory device is not mounted (provided that the case ofsupplying a highest voltage is excluded). That is because it isconsidered that heat sources and cooling objects are increased in numberand the passage of a cooling air current becomes worse by mounting theexternal memory device. Further, that is because the influence of anoise generated by the cooling fan comes to be relatively low even whenan increase in the rotation number makes the increased fan noise sincethe external memory device generates a noise.

[0043] Adjacent temperature zones are respectively set so as to overlapby 0.5° C., so that so-called hysteresis characteristics are provided.Thus, a frequent change from one temperature zone to another isprevented when the measured temperature is close to a boundary of eachtemperature zone.

[0044] Further, a limit value of the temperature (74° C. in the exampleof this Figure) is set, and when the measured temperature reaches thelimit temperature, the microcontroller 411 stops supply of the voltageto the central processing unit 401 and the drawing processor 403.

[0045] The control of the cooling fan 305 in the above constitution willbe explained. FIG. 10 is a flow chart for explaining processing by themicrocontroller 411 in this case.

[0046] When the entertainment apparatus is started, the microcontroller411 determines whether or not the external memory device is mounted froma state of the power line 413 of the external memory device. When themicrocontroller 411 determines that the external memory device ismounted, the microcontroller 411 refers to the graph applied when theexternal memory device is mounted. When the microcontroller 411determines that no external memory device is mounted, themicrocontroller 411 refers to the graph applied when the external memorydevice is not mounted (S101).

[0047] Then, the microcontroller 411 initializes the temperature zone(S102). In this example, the temperature zone is set to a lowest rangeof the applied temperature in the initialization. The microcontroller411 then supplies the cooling fan 305 with a voltage corresponding tothis temperature zone.

[0048] The value of a variable N as a counter is then set to zero(S103). The above counter is used to count the number of times of themeasured temperature serially exceeding the present temperature zonerange. This aims at changing one temperature zone to another when themeasured temperature exceeds the present temperature zone in serialthree temperature measurements by taking account of a case where noises,etc., cause a large error on the measured temperature. Two variables ofthe counter may be also used on upper and lower limit sides of thetemperature zone.

[0049] Then, the microcontroller 411 obtains the temperature measured bythe temperature sensor 404 near the central processing unit 401 (S104).The microcontroller 411 then referrs to the correspondece table for thefan control, to determine whether or not the temperature reaches a limitvalue (S105). When the temperature reaches the limit value, themicrocontroller 411 terminates the supply of the voltage to the centralprocessing unit 401 and the drawing processor 403 (S106). When thistemperature does not reach the limit value, the microcontroller 411refers to the correspondence table for the fan control, to determinewhether or not the obtained temperature is outside the range of thepresent temperature zone (S107).

[0050] When no obtained temperature is outside the range of the presenttemperature zone, i.e., when the obtained temperature is within therange of the present temperature zone, the value of the variable N isreset to zero (S108). The microcontroller 411 then determines whetherthe external memory device is attached or detached from the state of thepower line 413 of the external memory device (S113).

[0051] When the obtained temperature is outside the range of the presenttemperature zone, the value of N is increased by one (S109). Themicrocontroller 411 then determines whether or not the value of N comesto be 3 (S110). If the value of N is not 3, the microcontroller 411 doesnot change the temperature zone and determines the attachment-detachmentof the external memory device since it determines that no change oftemperature zones serially takes three times (S113). When the value of Nis 3, the temperature zone is changed to another since it determinesthat the obtained temperature comes to be outside the range of thepresent temperature zone serially three times (S111). In this case, whenthe obtained temperature is lower than the lower limit of the presenttemperature zone by referring to the correspondence table for the fancontrol, the microcontroller 411 changes the temperature zone to anothertemperature zone for increasing the voltage supplied to the cooling fan305. When the obtained temperature is higher than the upper limit of thepresent temperature zone, the microcontroller 411 changes thetemperature zone to another temperature zone for decreasing the voltagesupplied to the cooling fan 305. Then, the value of the variable N isreset to zero (S112).

[0052] As described above, in the determination of attaching-detaching(S113) of the external memory device, the microcontroller 411 checks thestate of the power line 413 of the external memory device, to determinewhether or not there is a change in the attachment-detachment of theexternal memory device. As a result, when there is a change in theattachment-detachment, the process returns to the processing in S102,and the referred graph is changed to another, and the presenttemperature zone is set to that in an initial state when the externalmemory device is attached or detached. On the other hand, when there isno change in the attachment-detachment, the process returns to theprocessing in S104, and the temperature is obtained. The determinationof attaching-detaching of the external memory device may be madeseparately from the processing shown in the flow chart of this Figure,and initialization processing (S102) of the temperature zone may beperformed by interruption when there is a change in theattachment-detachment.

[0053] While there may be employed any cycle time of the above series ofprocessings for obtaining the temperature and determining the change inthe temperature zone, it can be set to, e.g., a predetermined period(250 m seconds, one second, etc.).

[0054] While the above example explains an embodiment in which thesupplied voltage corresponds to the temperature zone, there may beemployed an embodiment in which, for example, the temperature and thesupplied voltage correspond to each other. This embodiment does notrequire the counter measurement or the determination of the change inthe temperature zone, etc., so that the processing of themicrocontroller 411 can be simplified.

[0055] In accordance with the present invention, therefore, therefore,it is possible to perform suitable control of the cooling fan dependingupon the attaching and detaching states of the external memory device,etc. in the information processing device that permits internal mountingof the external memory device, etc.

What is claimed is:
 1. A method of controlling a cooling fan in an information processing device that permits internal mounting of a relevant device, comprising the steps of: obtaining an internal temperature of the information processing device; obtaining an attaching-detaching state of the relevant device; obtaining a value relative to a rotation speed of the cooling fan which rotation speed corresponds to the obtained temperature, by referring to data which shows the relationship between the value relative to the rotation speed of the cooling fan and the temperature, and is determined depending upon the attaching-detaching state of the relevant device; and controlling the rotation speed of the cooling fan on the basis of the value relative to the rotation speed of the cooling fan.
 2. An information processing device that permits internal mounting of a relevant device, comprising: a cooling fan having variable rotation speeds, temperature obtaining means that obtains a temperature within the information processing device, attaching-detaching state obtaining means that obtains an attaching-detaching state of the relevant device, control means that controls the rotation speed of the cooling fan; and reference data storage means that stores reference data, which is determined depending upon attaching-detaching state of the relevant device, showing the relationship between a value relative to the rotation speed of the cooling fan and the temperature, wherein said control means determines the reference data to be referred to, on the basis of the attaching-detaching state of the relevant device obtained by the attaching-detaching state obtaining means, calculates the value relative to the rotation speed of the cooling fan from the temperature obtained by the temperature obtaining means and said reference data, and controls the rotation speed of the cooling fan on the basis of the obtained value.
 3. The information processing device according to claim 2, wherein said value relative to the rotation speed of the cooling fan is a voltage supplied to the cooling fan.
 4. The information processing device according to claim 2, wherein the reference data showing the relationship between the value relative to the rotation speed of the cooling fan and the temperature and being determined depending upon attaching-detaching state of said relevant device are determined such that, when the temperatures are at the same level, the rotation speed of the cooling fan when the relevant device is mounted is not smaller than the rotation speed of the cooling fan when the relevant device is not mounted.
 5. The information processing device according to claim 2, wherein said control means stops arithmetic processing of the information processing device when the temperature obtained by the temperature obtaining means is equal to, or greater than, a predetermined value.
 6. A program executable by an information processing device that permits internal mounting of a relevant device and comprises a cooling fan able to change its rotation speed, temperature obtaining means that obtains a temperature within the information processing device, attaching-detaching state obtaining means that obtains an attaching-detaching state of the relevant device, and control means that controls the rotation speed of the cooling fan, wherein the program causes said control means to execute the steps of: processing for referring to the reference data, which is determined depending upon the attaching-detaching state of the relevant device, showing the relationship between a value relative to the rotation speed of the cooling fan and the temperature; and processing for determining the reference data to be referred to, from the attaching-detaching state of the relevant device obtained by said attaching-detaching state obtaining means, calculating the value relative to the rotation speed of the cooling fan from the temperature obtained by the temperature obtaining means and said data for reference, and controlling the rotation speed of the cooling fan on the basis of this calculated value.
 7. A recording medium that stores the program recited in claim 6 and is readable by an information processing device. 